Tickets Day Passes Childcare Housing FAQ


A Festival of Writers Who are Wrong on the Internet

But Striving To Be Less So

Berkeley, CA, Lighthaven: May 31 - Jun 2
What is LessOnline?

31 May - 2 June, 2024

Lighthaven Campus, Berkeley, CA

LessOnline is a festival celebrating truth-seeking, optimization, and blogging. It's an opportunity to meet people you've only ever known by their LessWrong username or Substack handle.

The goal is to bring together a "mostly-online subculture of people trying to work together to figure out how to distinguish truth from falsehood using insights from probability theory, cognitive science, and AI." [1]

The weekend will be filled with talks, workshops, puzzle-hunts, dance parties, and late-night conversations around the fireside. If you have a session or activity you might like to run at LessOnline, let us know!

Lighthaven felt rambly and wondrous and fun without being pretentious? Felt like an incredibly-well-executed, 11-of-10 house party venue (laudatory) crossed with Disneyland.

      ——A Lighthaven Event Attendee

Some writings we love

These sites embody the virtues we want to celebrate. We're offering free tickets to everyone whose site is listed below.

This list is incomplete. You can help by expanding it.

Some attending guests

Kevin Simler
Melting Asphalt
Cremieux Recueil
Scott Alexander
Astral Codex Ten
Eliezer Yudkowsky
The Sequences and HPMOR
Joe Carlsmith
Nate Soares
Minding Our Way
Alexander Wales
Rob Bensinger
Nothing is Mere
Patrick McKenzie
Bits About Money
Sarah Constantin
Rough Diamonds
Agnes Callard
The Point
Scott Sumner
The Money Illusion

Things That Will Happen

Writing Workshops

Advice from great writers,
and space to apply it

Rationality Classes

Get calibrated and identify cruxes

Puzzle Hunts

Unravel mysteries across a sprawling venue

Dance Party

New music by the
Fooming Shoggoths

Manifest 2024

Manifest (Fri Jun 7 - Sun Jun 9) is a festival for forecasting and prediction markets, hosted by Manifold and Manifund.

It's happening one week after LessOnline, both at Lighthaven.

So we're teaming up with Manifest to offer a discounted ticket to both events, as well as a weeklong Summer Camp in between the two.

If you'd like to pay for your Manifest ticket in mana, Manifold is offering various discounts; see their ticketing site for more details.

Buy Tickets

Tickets include (a) admission to the Lighthaven venue, (b) lunch, dinner, and snacks, and (c) many talks, workshops, and events. Housing and childcare can be purchased separately below.

Really want to come but can't afford the tickets? Fill out this form.

One-Day Passes

A single day's access to the Lighthaven Campus (either Saturday or Sunday, your choice), 2 hot-meals and snacks, and access to all sessions happening that day.

Day Pass


Supporter Ticket

For those who want to support LessWrong run independently.

Comes with a full week of access to the Lighthaven Campus May 31st – June 9th.

Supporter Ticket


Families & Childcare

LessOnline is a family-friendly event! Bring your kids, we'd love to see them :-)

  • For ages 2-10, tickets are $50/event, and below that age kids come free.
  • We'll be offering a day care service onsite, from 10 AM to 7 PM.
  • Daycare pricing is $30/hour, or around $10/hour if you book ahead of time.

If you'd like childcare outside the hours of 10 AM to 7 PM, please indicate it on the booking form and we will connect you with a nanny service at $45/hour.

Child Tickets (+Daycare)

Each ticket comes with the two possible day-care add-ons. Remove one or both of the add-ons when you buy your child's ticket.

LessOnline Child Ticket: $50 Summer Camp Child Ticket: $50 Manifest Child Ticket: $50

Housing at Lighthaven

A limited number of rooms are available on-site at Lighthaven. Housing is also available during Summer Camp (Mon Jun 3 - Fri Jun 7) and Manifest (Fri Jun 7 - Sun Jun 9).

Book rooms